Stop Python-interpolating payday.sql

Using Python string interpolation on the payday.sql file introduces
complexity that leads to bugs. The one I hit was using '%' for
interplation in a Postgres RAISES clause: it would've had to be escaped
to make it through the Python interpolation.

gratipay/billing/payday.py

@@ -103,15 +103,9 @@ def start(cls):
             """, back_as=dict)
             log("Starting a new payday.")
         except IntegrityError:  # Collision, we have a Payday already.
-            d = cls.db.one("""
-                SELECT id, (ts_start AT TIME ZONE 'UTC') AS ts_start, stage
-                  FROM paydays
-                 WHERE ts_end='1970-01-01T00:00:00+00'::timestamptz
-            """, back_as=dict)
+            d = cls.db.one("SELECT current_payday();", back_as=dict)
             log("Picking up with an existing payday.")
 
-        d['ts_start'] = d['ts_start'].replace(tzinfo=aspen.utils.utc)
-
         log("Payday started at %s." % d['ts_start'])
 
         payday = Payday()
@@ -154,7 +148,7 @@ def payin(self):
         money internally between participants.
         """
         with self.db.get_cursor() as cursor:
-            self.prepare(cursor, self.id, self.ts_start)
+            self.prepare(cursor)
             holds = self.create_card_holds(cursor)
             self.process_subscriptions(cursor)
             self.transfer_takes(cursor, self.ts_start)
@@ -177,10 +171,10 @@ def payin(self):
 
 
     @staticmethod
-    def prepare(cursor, payday_id, ts_start):
+    def prepare(cursor):
         """Prepare the DB: we need temporary tables with indexes and triggers.
         """
-        cursor.run(PAYDAY, dict(payday_id=payday_id, ts_start=ts_start))
+        cursor.run(PAYDAY)
         log('Prepared the DB.')
 
 

sql/branch.sql

@@ -3,6 +3,18 @@ BEGIN;
     DROP TABLE payments;
 
 
+    CREATE FUNCTION current_payday() RETURNS SETOF paydays AS $$
+        SELECT *
+          FROM paydays
+         WHERE ts_end='1970-01-01T00:00:00+00'::timestamptz;
+    $$ LANGUAGE sql;
+
+    CREATE FUNCTION current_payday_id() RETURNS int AS $$
+        -- This is a function so we can use it in DEFAULTS for a column.
+        SELECT id FROM current_payday();
+    $$ LANGUAGE sql;
+
+
     -- Accounts
 
     CREATE TYPE account_type AS ENUM ('asset', 'liability', 'income', 'expense');

sql/payday.sql

@@ -18,7 +18,7 @@ CREATE TABLE payday_participants AS
           , braintree_customer_id
       FROM participants p
      WHERE is_suspicious IS NOT true
-       AND claimed_time < %(ts_start)s
+       AND claimed_time < (SELECT ts_start FROM current_payday())
   ORDER BY claimed_time;
 
 CREATE UNIQUE INDEX ON payday_participants (id);
@@ -49,14 +49,14 @@ CREATE TABLE payday_teams AS
 
 DROP TABLE IF EXISTS payday_journal_so_far;
 CREATE TABLE payday_journal_so_far AS
-    SELECT * FROM journal WHERE payday = %(payday_id)s;
+    SELECT * FROM journal WHERE payday = (SELECT id FROM current_payday());
 
 DROP TABLE IF EXISTS payday_subscriptions;
 CREATE TABLE payday_subscriptions AS
     SELECT subscriber, team, amount
       FROM ( SELECT DISTINCT ON (subscriber, team) *
                FROM subscriptions
-              WHERE mtime < %(ts_start)s
+              WHERE mtime < (SELECT ts_start FROM current_payday())
            ORDER BY subscriber, team, mtime DESC
            ) s
       JOIN payday_participants p ON p.username = s.subscriber
@@ -93,13 +93,14 @@ CREATE TABLE payday_journal
 , amount numeric(35,2)  NOT NULL
 , debit bigint          NOT NULL
 , credit bigint         NOT NULL
-, payday int            DEFAULT %(payday_id)s
+, payday int            NOT NULL DEFAULT current_payday_id()
  );
 
 CREATE OR REPLACE FUNCTION payday_update_balance() RETURNS trigger AS $$
 DECLARE
-    to_debit    text;
-    to_credit   text;
+    to_debit            text;
+    to_credit           text;
+    balance_after_debit numeric(35, 2);
 BEGIN
     to_debit = (SELECT participant FROM accounts WHERE id=NEW.debit);
     IF to_debit IS NOT NULL THEN

tests/py/test_billing_payday.py

@@ -172,17 +172,16 @@ def test_start_prepare(self, log):
         self.make_participant('carl', balance=10, claimed_time='now')
 
         payday = Payday.start()
-        ts_start = payday.ts_start
 
         get_participants = lambda c: c.all("SELECT * FROM payday_participants")
 
         with self.db.get_cursor() as cursor:
-            payday.prepare(cursor, payday.id, ts_start)
+            payday.prepare(cursor)
             participants = get_participants(cursor)
 
         expected_logging_call_args = [
             ('Starting a new payday.'),
-            ('Payday started at {}.'.format(ts_start)),
+            ('Payday started at {}.'.format(payday.ts_start)),
             ('Prepared the DB.'),
         ]
         expected_logging_call_args.reverse()
@@ -192,13 +191,12 @@ def test_start_prepare(self, log):
         log.reset_mock()
 
         # run a second time, we should see it pick up the existing payday
-        payday = Payday.start()
-        second_ts_start = payday.ts_start
+        second_payday = Payday.start()
         with self.db.get_cursor() as cursor:
-            payday.prepare(cursor, second_payday.id, ts_start)
+            payday.prepare(cursor)
             second_participants = get_participants(cursor)
 
-        assert ts_start == second_ts_start
+        assert payday.ts_start == second_payday.ts_start
         participants = list(participants)
         second_participants = list(second_participants)
 
@@ -208,7 +206,7 @@ def test_start_prepare(self, log):
 
         expected_logging_call_args = [
             ('Picking up with an existing payday.'),
-            ('Payday started at {}.'.format(second_ts_start)),
+            ('Payday started at {}.'.format(second_payday.ts_start)),
             ('Prepared the DB.'),
         ]
         expected_logging_call_args.reverse()
@@ -239,7 +237,7 @@ class TestPayin(BillingHarness):
     def create_card_holds(self):
         payday = Payday.start()
         with self.db.get_cursor() as cursor:
-            payday.prepare(cursor, payday.id, payday.ts_start)
+            payday.prepare(cursor)
             return payday.create_card_holds(cursor)
 
     @mock.patch.object(Payday, 'fetch_card_holds')
@@ -370,7 +368,7 @@ def test_payin_cant_make_balances_more_negative(self):
         """)
         payday = Payday.start()
         with self.db.get_cursor() as cursor:
-            payday.prepare(cursor, payday.id, payday.ts_start)
+            payday.prepare(cursor)
             cursor.run("""
                 UPDATE payday_participants
                    SET new_balance = -50
@@ -408,7 +406,7 @@ def test_payday_journal_updates_participant_and_team_balances_for_payroll(self):
 
         payday = Payday.start()
         with self.db.get_cursor() as cursor:
-            payday.prepare(cursor, payday.id, payday.ts_start)
+            payday.prepare(cursor)
 
             cursor.run("UPDATE payday_teams SET balance=20 WHERE slug='TheATeam'")
             cursor.run("""
@@ -432,7 +430,7 @@ def test_payday_journal_updates_participant_and_team_balances_for_subscriptions(
 
         payday = Payday.start()
         with self.db.get_cursor() as cursor:
-            payday.prepare(cursor, payday.id, payday.ts_start)
+            payday.prepare(cursor)
 
             cursor.run("""
                 INSERT INTO payday_journal
@@ -453,7 +451,7 @@ def test_payday_journal_disallows_negative_payday_team_balance(self):
 
         payday = Payday.start()
         with self.db.get_cursor() as cursor:
-            payday.prepare(cursor, payday.id, payday.ts_start)
+            payday.prepare(cursor)
             cursor.run("UPDATE payday_teams SET balance=10 WHERE slug='TheATeam'")
             with pytest.raises(IntegrityError):
                 cursor.run("""
@@ -471,7 +469,7 @@ def test_payday_journal_disallows_negative_payday_participant_balance(self):
 
         payday = Payday.start()
         with self.db.get_cursor() as cursor:
-            payday.prepare(cursor, payday.id, payday.ts_start)
+            payday.prepare(cursor)
             with pytest.raises(IntegrityError):
                 cursor.run("""
                     INSERT INTO payday_journal
@@ -494,7 +492,7 @@ def test_process_subscriptions(self):
 
         payday = Payday.start()
         with self.db.get_cursor() as cursor:
-            payday.prepare(cursor, payday.id, payday.ts_start)
+            payday.prepare(cursor)
             payday.process_subscriptions(cursor)
             assert cursor.one("select balance from payday_teams where slug='TheATeam'") == D('0.51')
             assert cursor.one("select balance from payday_teams where slug='TheBTeam'") == 0
@@ -526,7 +524,7 @@ def test_transfer_takes(self):
         # have already been processed
         for i in range(3):
             with self.db.get_cursor() as cursor:
-                payday.prepare(cursor, payday.id, payday.ts_start)
+                payday.prepare(cursor)
                 payday.transfer_takes(cursor, payday.ts_start)
                 payday.update_balances(cursor)
 
@@ -550,7 +548,7 @@ def test_process_draws(self):
 
         payday = Payday.start()
         with self.db.get_cursor() as cursor:
-            payday.prepare(cursor, payday.id, payday.ts_start)
+            payday.prepare(cursor)
             payday.process_subscriptions(cursor)
             payday.transfer_takes(cursor, payday.ts_start)
             payday.process_draws(cursor)
@@ -588,7 +586,7 @@ def test_take_over_during_payin(self):
         alice.set_tip_to(bob, 18)
         payday = Payday.start()
         with self.db.get_cursor() as cursor:
-            payday.prepare(cursor, payday.id, payday.ts_start)
+            payday.prepare(cursor)
             bruce = self.make_participant('bruce', claimed_time='now')
             bruce.take_over(('twitter', str(bob.id)), have_confirmation=True)
             payday.process_subscriptions(cursor)